Astrophysics and Astronomy Commons^™

Deep Learning Applications For Secondary Cosmic Microwave Background Anisotropies, Eric Guzman

Physics Theses and Dissertations

Next-generation cosmic microwave background (CMB) surveys will map the microwave sky with unprecedented precision presenting a wide range of opportunities for new insights into cosmology. To maximize the scientific value of upcoming surveys, new methods that can disentangle primary and secondary CMB anisotropies are required. The CMB secondaries encode information about the cosmological sources that cause them and act as a source of noise in the observation of primary anisotropies. Quadratic estimators are the current standard techniques for reconstruction of the sources of CMB secondaries. While successful for reconstruction of distortion fields with current data, quadratic estimators will become sub-optimal …

Comet Nuclei Activity Simulation Using Percolation Theory On Comet 67p/Churyumov– Gerasimenko, Ahmad Sohani

Theses and Dissertations

Comets, remnants of the solar system's formation, exhibits partially unexplained outbursts that are closely tied to the physical structure of the nucleus. To investigate outbursts, we employed pore network modeling techniques, such as the Bower-Watson algorithm and Voronoi diagrams, to better represent the nucleus' complex porous structure and simulate gas transfer processes. We examined heat diffusion in the comet's subsurface and its influence on crystallization. The extra heat generated by crystallization can shift the crystalline front deeper into the nucleus, accelerating subsurface evaporation rates. This process results in the formation of a thicker ice mantle with reduced porosity on the …

Du Undergraduate Showcase: Research, Scholarship, And Creative Works, Caitlyn Aldersea, Justin Bravo, Sam Allen, Anna Block, Connor Block, Emma Buechler, Maria De Los Angeles Bustillos, Arianna Carlson, William Christensen, Olivia Kachulis, Noah Craver, Kate Dillon, Muskan Fatima, Angel Fernandes, Emma Finch, Colleen Cassidy, Amy Fishman, Andrea Francis, Stacia Fritz, Simran Gill, Emma Gries, Rylie Hansen, Shannon Powers, Jacqueline Martinez, Zachary Harker, Ashley Hasty, Mykaela Tanino-Springsteen, Kathleen Hopps, Adelaide Kerenick, Colin Kleckner, Ci Koehring, Elijah Kruger, Braden Krumholz, Maddie Leake, Lyneé Alves, Seraphina Loukas, Yatzari Lozano Vazquez, Haley Maki, Emily Martinez, Sierra Mckinney, Audrey Mitchell, Kipling Newman, Audrey Ng, Megan Lucyshyn, Andrew Nguyen, Stevie Ostman, Casandra Pearson, Alexandra Penney, Julia Gielczynski, Tyler Ball, Anna Rini, Christina Rorres, Simon Ruland, Helayna Schafer, Emma Sellers, Sarah Schuller, Claire Shaver, Kevin Summers, Isabella Shaw, Madison Sinar, Claudia Pena, Apshara Siwakoti, Carter Sorensen, Madi Sousa, Anna Sparling, Alexandra Revier, Brandon Thierry, Dylan Tyree, Maggie Williams, Lauren Wols

DU Undergraduate Research Journal Archive

DU Undergraduate Showcase: Research, Scholarship, and Creative Works

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

Perspective Sky: A New Architectural Typology For Astronomy, Brendan Lydic

Bachelor of Architecture Theses - 5th Year

This thesis aims to reconnect modern humans to the night sky and the universe around us. A connection that has been lost to a multitude of barriers and distractions. Physical barriers like air and light pollution, and distractions like technology and overwhelming world events. I aim to restore this connection by creating a new architectural typology for the observation of and education about the night sky, the cosmos, and astronomy. It will serve as a site of pilgrimage, where visitors of all ages can re-engage with the stars and reintroduce themselves to the perspective of our ancestors. The questions I …

Glitch Subtraction From Gravitational Wave Data Using Adaptive Spline Fitting, Soumya D. Mohanty, Mohammad A. T. Chowdhury

Physics & Astronomy Faculty Publications

Transient signals of instrumental and environmental origins ("glitches") in gravitational wave data elevate the false alarm rate of searches for astrophysical signals and reduce their sensitivity. Glitches that directly overlap astrophysical signals hinder their detection and worsen parameter estimation errors. As the fraction of data occupied by detectable astrophysical signals will be higher in next generation detectors, such problematic overlaps could become more frequent. These adverse effects of glitches can be mitigated by estimating and subtracting them out from the data, but their unpredictable waveforms and large morphological diversity pose a challenge. Subtraction of glitches using data from auxiliary sensors …

Improvements To Isru For Rocket Fuel Generation, Justin Sharp

James Madison Undergraduate Research Journal (JMURJ)

The development of efficient in-situ resource utilization (ISRU) technologies is crucial for the establishment of an extraterrestrial, self-sustaining colony. The generation of rocket fuel at potential colony locations is necessary to provide the transportation of people and cargo to and from these locations.Three processes are discussed for the improvement of ISRU methods to generate rocket fuel: electrolysis and electrochemical improvements to the process of crude fuel production, physical and chemical methods for separation of gaseous H2 and O2, and materials and cryogenics engineering for storage and transportation of liquid hydrogen (LH2) and liquid oxygen (LOX). Storage and transportation of cryogenics …

Transit Photometry Of Multiple Exoplanet Watch Targets, Jonah Becken

Celebrating Scholarship and Creativity Day (2018-)

Since 1995 exoplanet research has increase dramatically, as a result it is more important than ever to precisely know the dates and times of future transits for repeated observations of a target. NASA’s Exoplanet Watch database and accompanying light curve producing code EXOTIC have the goal of allowing small observatories across the world help find future transits. Under these objective observations of known exoplanet transits where made, using the Saint John’s University observatory, to find the transit midpoint, the ratio of the planet radius and the solar radius, and the period. Using these values, the confirmation that a transit happened …

Seasonal And Diurnal Variations Of Kelvin-Helmholtz Instability At Terrestrial Magnetopause, S. Kavosi, J. Raeder, Jay R. Johnson, K. Nykyri, C. J. Farrugia

Faculty Publications

Kelvin-Helmholtz Instability is ubiquitous at Earth’s magnetopause and plays an important role in plasma entry into the magnetosphere during northward interplanetary magnetic fields. Here, using one solar cycle of data from NASA THEMIS (Time History of Events and Macro scale Interactions during Substorms) and MMS (Magnetospheric Multiscale) missions, we found that KHI occurrence rates show seasonal and diurnal variations with the rate being high near the equinoxes and low near the solstices. The instability depends directly on the Earth’s dipole tilt angle. The tilt toward or away from the Sun explains most of the seasonal and diurnal variations, while the …

Red Riding On Hood: Exploring How Galaxy Colour Depends On Environment, Pankaj C. Bhambhani, Ivan K. Baldry, Sarah Brough, Alexander D. Hill, M A. Lara-Lopez, J Loveday, Benne Holwerda

Faculty and Staff Scholarship

Galaxy populations are known to exhibit a strong colour bimodality, corresponding to blue star-forming and red quiescent subpopulations. The relative abundance of the two populations has been found to vary with stellar mass and environment. In this paper, we explore the effect of environment considering different types of measurements. We choose a sample of 49 911 galaxies with 0.05 < z < 0.18 from the Galaxy And Mass Assembly survey. We study the dependence of the fraction of red galaxies on different measures of the local environment as well as the large-scale `geometric’ environment defined by density gradients in the surrounding cosmic web. We find that the red galaxy fraction varies with the environment at fixed stellar mass. The red fraction depends more strongly on local environmental measures than on large-scale geometric environment measures. By comparing the different environmental densities, we show that no density measurement fully explains the observed environmental red fraction variation, suggesting the different measures of environmental density contain different information. We test whether the local environmental measures, when combined together, can explain all the observed environmental red fraction variation. The geometric environment has a small residual effect, and this effect is larger for voids than any other type of geometric environment. This could provide a test of the physics applied to cosmological-scale galaxy evolution simulations as it combines large-scale effects with local environmental impact.

Mapping Galactic Acceleration With Pulsar Timing, Abigail Moran

University Scholar Projects

We have conducted a cross match of objects in Gaia Early Data Release 3 and millisecond pulsars (MSPs) in the International Pulsar Timing Array’s Data Release 2 (IPTA DR2) to identify binary systems. Gaia has parallax measurements for these optical companions, which we combine with pulsar timing based parallax measurements to calculate new combined MSP distances. Through this crossmatch with IPTA DR2 we improved five distance measurements and found the first parallax measurement for one MSP.

Using this Gaia crossmatch method now with a well-timed subset of the Australia Telescope National Facility’s database, we found three new pulsar distances. We …

Spinning Up A Daze: Tess Uncovers A Hot Jupiter Orbiting The Rapid Rotator Toi-778, J. T. Clark, B. C. Addison, J. Okumura, S. Vach, A. Errico, A. Heitzmann, J. E. Rodriguez, D. J. Wright, M. Clerté, C. J. Brown, T. Fetherolf, R. A. Wittenmyer, P. Plavchan, S. R. Kane, J. Horner, J. F. Kielkopf, A. Shporer, C. G. Tinney, L. Hui-Gen, S. Ballard, B. P. Bowler, M. W. Mengel, G. Zhou, A. S. Lee, A. David, J. Heim, M. E. Lee, V. Sevilla, N. E. Zafar, N. R. Hinkel, B. E. Allen, D. Bayliss, A. Berberyan, P. Berlind, A. Bieryla, F. Bouchy, R. Brahm, E. M. Bryant, J. L. Christiansen, D. R. Ciardi, K. N. Ciardi, K. A. Collins, J. Dallant, A. B. Davis, M. R. Díaz, C. D. Dressing, G. A. Esquerdo, J.-V. Harre, S. B. Howell, J. M. Jenkins, Eric L.N. Jensen, M. I. Jones, A. Jordán, D. W. Latham, M. B. Lund, J. Mccormac, L. D. Nielsen, J. Otegi, S. N. Quinn, D. J. Radford, G. R. Ricker, R. P. Schwarz, S. Seager, A. M. S. Smith, C. Stockdale, T.-G. Tan, S. Udry, R. Vanderspek, M. N. Günther, S. Wang, G. Wingham, J. N. Winn

Physics & Astronomy Faculty Works

NASA's Transiting Exoplanet Survey Satellite (TESS) mission has been uncovering a growing number of exoplanets orbiting nearby, bright stars. Most exoplanets that have been discovered by TESS orbit narrow-line, slow-rotating stars, facilitating the confirmation and mass determination of these worlds. We present the discovery of a hot Jupiter orbiting a rapidly rotating (v sin (i) = 35.1 ± 1.0 km s⁻¹) early F3V-dwarf, HD 115447 (TOI-778). The transit signal taken from Sectors 10 and 37 of TESS's initial detection of the exoplanet is combined with follow-up ground-based photometry and velocity measurements taken from Minerva-Australis, TRES, CORALIE, and …

Analysis On High Mass X-Ray Binary Spectral Shape Dependence On Luminosity For Ngc3310, Izabela Pavel

Physics Undergraduate Honors Theses

In most normal galaxies, the most X-ray luminous sources are high-mass X-ray binaries (HMXBs), which are binary star systems that contain compact objects (black holes or neutron stars) accreting from massive (> 8M⊙) companion stars. These HMXBs are thought to have been important sources of ionizing emission within star-forming galaxies that may have contributed to the heating of the intergalatic medium (gas over large cosmic scales) in the early Universe. When studying how HMXBs contribute to interstellar medium feedback, a single spectral shape of an absorbed power-law is typically assumed to be universal. The goal of this thesis is to …

Insights Into Star Formation And Agn Activity In Protocluster Environments From Morphological Studies And Sed Fitting, Erik B. Monson

Graduate Theses and Dissertations

In this dissertation I present work done from 2018-2023 to investigate the growth of galaxies and supermassive black holes (SMBH) in high redshift overdensities (protoclusters) by studying the star-forming galaxy and active galactic nucleus (AGN) population in the SSA22 protocluster. I examined possible environmental sources of the enhanced star formation and AGN activity in the z = 3.09 SSA22 protocluster using Hubble WFC3 ∼ 1.6 μm observations of the SSA22 field, including new observations centered on eight X-ray selected protocluster AGN. To investigate the role of mergers in the observed AGN and star formation enhancement, quantitative and visual morphological classifications …

Mach And Froude Numbers On Mars., Camella-Rosa Nasr

Electronic Theses and Dissertations

Mars atmospheric global circulation models exhibit transonic jet streaks during
northern winter, which motivates this study of the Mach number, Ma (the ratio of
flow speed to the speed of sound), and the Froude number, Fr (the ratio of flow
speed to the speed of buoyancy waves), as a function of season and location. Two
global reanalyses spanning Mars Years (MY) 24 to 33 are used as input, EMARS
and OpenMARS. The study’s vertical coordinate is the isentropic variable potential
temperature, θ, ranging from θ = 125 to 1100 K, which corresponds to altitudes
ranging on average from z ≈ …

Testing The Interaction Between A Substellar Companion And A Debris Disk In The Hr 2562 System, Stella Yimiao Zhang, Gaspard Duchêne, Robert J. De Rosa, Megan Ansdell, Quinn Konopacky, Thomas Esposito, Eugene Chiang, Malena Rice, Brenda Matthews, Paul Kalas, Bruce Macintosh, Franck Marchis, Stan Metchev, Jenny Patience, Julien Rameau, Kimberly Ward-Duong, Schuyler Wolff, Michael P. Fitzgerald, Vanessa P. Bailey, Travis S. Barman, Joanna Bulger, Christine H. Chen, Jeffrey K. Chilcotte, Tara Cotten, René Doyon, Katherine B. Follette, Benjamin L. Gerard, Stephen Goodsell, James R. Graham, Alexandra Z. Greenbaum, Pascale Hibon, Li Wei Hung

Astronomy: Faculty Publications

The HR 2562 system is a rare case where a brown dwarf companion resides in a cleared inner hole of a debris disk, offering invaluable opportunities to study the dynamical interaction between a substellar companion and a dusty disk. We present the first ALMA observation of the system as well as the continued Gemini Planet Imager monitoring of the companion's orbit with six new epochs from 2016 to 2018. We update the orbital fit, and in combination with absolute astrometry from GAIA, place a 3σ upper limit of 18.5 M J on the companion's mass. To interpret the ALMA observations, …

The Loneliest Galaxies In The Universe: A Gama And Galaxy Zoo Study On Void Galaxy Morphology., Lori E. Porter

College of Arts & Sciences Senior Theses

The large-scale structure (LSS) of the Universe is comprised of galaxy filaments, tendrils, and voids. The majority of the Universe’s volume is taken up by these voids, which exist as underdense, but not empty, regions. The galaxies found inside voids are void galaxies and expected to be some of the most isolated objects in the Universe. However, their standard morphology remains poorly studied. This study, using the Galaxy and Mass Assembly (GAMA) data and Galaxy Zoo survey, aims to remedy this. For completeness purposes, we use void galaxies identified by Alpaslan et al. (2014) with stellar masses (M*) of 10 …

On The Impact Of Inclination-Dependent Attenuation On The Derived Star Formation Histories Of Disk Galaxies, Keith Doore

Graduate Theses and Dissertations

The physical properties of a galaxy (e.g., its star-formation history and dust content) regulate the distribution of light that is emitted by stars and attenuated by the interstellar gas and dust. This attenuation by dust can have a significant impact on the observed spectral energy distribution (SED) of a disk galaxy, especially when taking into account its viewing angle (i.e., inclination). For example, as the inclination angle of a galactic disk changes from face-on to edge-on (i.e., i = 0 deg to i = 90 deg), the proportion of light that is attenuated along the line of sight increases, due …

Joint Constraints On Kepler-36 From Kepler And New Keck-Hires Data, Nicholas Juliano

UNLV Theses, Dissertations, Professional Papers, and Capstones

I analyze new HIRES Radial Velocity (RV) data in conjunction with transit mid-times and uncertainties from the full 17 quarters of Kepler data to reassess the orbital parameters of the Kepler-36 system. Six additional RV measurements were taken by the Keck-HIRES spectrograph from September 21, 2021 to October 11, 2021. I carry out a differential evolution Markov Chain Monte Carlo-based (DEMCMC) analysis to infer improved orbital elements for the two known planets in the system. Leveraging additional information provided by the new RV measurements, I extend this DEMCMC analysis to a possible three-planet configuration. I explore the likelihood of a …

Identifying And Analyzing Multi-Star Systems Among Tess Planetary Candidates Using Gaia, Katie E. Bailey

Electronic Theses and Dissertations

Exoplanets represent a young, rapidly advancing subfield of astrophysics where much is still unknown. It is therefore important to analyze trends among their parameters to learn more about these systems. More complexity is added to these systems with the presence of additional stellar companions. To study these complex systems, one can employ programming languages such as Python to parse databases such as those constructed by TESS and Gaia to bridge the gap between exoplanets and stellar companions. Data can then be analyzed for trends in these multi-star exoplanet systems and in juxtaposition to their single-star counterparts. This research was able …